Laser video projection system and method with anti-piracy feature

Abstract

A pulsed laser device and a laser display system using the pulsed laser device are disclosed that thwart recording of displayed video images with electronic imaging devices. The pulsed laser device is Q-switched, whereby the Q-switch trigger pulses have a temporal pattern that includes a blanking period of a duration that is longer than a repetition time between consecutive trigger pulses and shorter than a time period perceived by the human eye. The output beam of the Q-switched pulse laser is frequency-converted by non-linear optical frequency conversion into an imaging beam, for example, a three-color RBG beam, that can be modulated for displaying color images. The blanking period renders the displayed images practically unsuitable for off-screen recording with electronic image recording devices, such as CCD movie cameras.

Description

CROSS-REFERENCE TO OTHER PATENT APPLICATIONS[0001]This application claims the benefit of U.S. provisional Patent Application No. 60 / 475,422, filed Jun. 3, 2003, the content of which is incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]The invention is directed to a laser video projection system, and more particularly to a laser video projection system for digital motion pictures that thwarts recording of the projected image with a camcorder or an electronic camera.[0003]Piracy and illegal copying of digital audio and video material has become widespread with the availability of inexpensive CD and DVD burners. This threatens the existence of record labels and of movie studios and motion picture distributors. One way of producing illegal copies is to intercept file content from a legal copy of copyrighted work, either by making an illegal copy of a CD / DVD or by intercepting data transferred, for example, from a movie studio to a movie theater intended for digital proje...

AI Technical Summary

Problems solved by technology

Piracy and illegal copying of digital audio and video material has become widespread with the availability of inexpensive CD and DVD burners.

This threatens the existence of record labels and of movie studios and motion picture distributors.

Moreover, making illegal copies from CD / DVD may become unworkable due to security features added to the original recording.

However, camcorders with a response time in the order of microseconds record during the brief moment the projector light is blocked an objectionable black stripe that moves across the picture.

Consequently, such recordings have little commercial value and are mainly found in countries where recordings are sold based on price alone, without regard for the quality of the recording.

Since there may be no perceivable image degradation, the pirate may produce an illegal copy with a CD burner and sell these copies to a wide market at a substantial profit.

The resulting distortion of the projected image is not perceived by the human eye, but produces an objectionable image pattern in a movie recorded off a projection screen.

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